/*
* Copyright (C) 2009-2012 the libgit2 contributors
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include "common.h"
#include "commit.h"
#include "tree.h"
#include "git2/repository.h"
#include "git2/object.h"
#define DEFAULT_TREE_SIZE 16
#define MAX_FILEMODE_BYTES 6
static bool valid_filemode(const int filemode)
{
return (filemode == GIT_FILEMODE_TREE
|| filemode == GIT_FILEMODE_BLOB
|| filemode == GIT_FILEMODE_BLOB_GROUP_WRITABLE
|| filemode == GIT_FILEMODE_BLOB_EXECUTABLE
|| filemode == GIT_FILEMODE_LINK
|| filemode == GIT_FILEMODE_COMMIT);
}
static int valid_entry_name(const char *filename)
{
return *filename != '\0' && strchr(filename, '/') == NULL;
}
static int entry_sort_cmp(const void *a, const void *b)
{
const git_tree_entry *entry_a = (const git_tree_entry *)(a);
const git_tree_entry *entry_b = (const git_tree_entry *)(b);
return git_path_cmp(
entry_a->filename, entry_a->filename_len, git_tree_entry__is_tree(entry_a),
entry_b->filename, entry_b->filename_len, git_tree_entry__is_tree(entry_b));
}
static git_tree_entry *alloc_entry(const char *filename)
{
git_tree_entry *entry = NULL;
size_t filename_len = strlen(filename);
entry = git__malloc(sizeof(git_tree_entry) + filename_len + 1);
if (!entry)
return NULL;
memset(entry, 0x0, sizeof(git_tree_entry));
memcpy(entry->filename, filename, filename_len);
entry->filename[filename_len] = 0;
entry->filename_len = filename_len;
return entry;
}
struct tree_key_search {
const char *filename;
size_t filename_len;
};
static int homing_search_cmp(const void *key, const void *array_member)
{
const struct tree_key_search *ksearch = key;
const git_tree_entry *entry = array_member;
const size_t len1 = ksearch->filename_len;
const size_t len2 = entry->filename_len;
return memcmp(
ksearch->filename,
entry->filename,
len1 < len2 ? len1 : len2
);
}
/*
* Search for an entry in a given tree.
*
* Note that this search is performed in two steps because
* of the way tree entries are sorted internally in git:
*
* Entries in a tree are not sorted alphabetically; two entries
* with the same root prefix will have different positions
* depending on whether they are folders (subtrees) or normal files.
*
* Consequently, it is not possible to find an entry on the tree
* with a binary search if you don't know whether the filename
* you're looking for is a folder or a normal file.
*
* To work around this, we first perform a homing binary search
* on the tree, using the minimal length root prefix of our filename.
* Once the comparisons for this homing search start becoming
* ambiguous because of folder vs file sorting, we look linearly
* around the area for our target file.
*/
static int tree_key_search(git_vector *entries, const char *filename, size_t filename_len)
{
struct tree_key_search ksearch;
const git_tree_entry *entry;
int homing, i;
ksearch.filename = filename;
ksearch.filename_len = filename_len;
/* Initial homing search; find an entry on the tree with
* the same prefix as the filename we're looking for */
homing = git_vector_bsearch2(entries, &homing_search_cmp, &ksearch);
if (homing < 0)
return homing;
/* We found a common prefix. Look forward as long as
* there are entries that share the common prefix */
for (i = homing; i < (int)entries->length; ++i) {
entry = entries->contents[i];
if (homing_search_cmp(&ksearch, entry) < 0)
break;
if (entry->filename_len == filename_len &&
memcmp(filename, entry->filename, filename_len) == 0)
return i;
}
/* If we haven't found our filename yet, look backwards
* too as long as we have entries with the same prefix */
for (i = homing - 1; i >= 0; --i) {
entry = entries->contents[i];
if (homing_search_cmp(&ksearch, entry) > 0)
break;
if (entry->filename_len == filename_len &&
memcmp(filename, entry->filename, filename_len) == 0)
return i;
}
/* The filename doesn't exist at all */
return GIT_ENOTFOUND;
}
void git_tree_entry_free(git_tree_entry *entry)
{
if (entry == NULL)
return;
git__free(entry);
}
git_tree_entry *git_tree_entry_dup(const git_tree_entry *entry)
{
size_t total_size;
git_tree_entry *copy;
assert(entry);
total_size = sizeof(git_tree_entry) + entry->filename_len + 1;
copy = git__malloc(total_size);
if (!copy)
return NULL;
memcpy(copy, entry, total_size);
return copy;
}
void git_tree__free(git_tree *tree)
{
unsigned int i;
for (i = 0; i < tree->entries.length; ++i) {
git_tree_entry *e = git_vector_get(&tree->entries, i);
git_tree_entry_free(e);
}
git_vector_free(&tree->entries);
git__free(tree);
}
const git_oid *git_tree_id(const git_tree *c)
{
return git_object_id((const git_object *)c);
}
git_filemode_t git_tree_entry_filemode(const git_tree_entry *entry)
{
return (git_filemode_t)entry->attr;
}
const char *git_tree_entry_name(const git_tree_entry *entry)
{
assert(entry);
return entry->filename;
}
const git_oid *git_tree_entry_id(const git_tree_entry *entry)
{
assert(entry);
return &entry->oid;
}
git_otype git_tree_entry_type(const git_tree_entry *entry)
{
assert(entry);
if (S_ISGITLINK(entry->attr))
return GIT_OBJ_COMMIT;
else if (S_ISDIR(entry->attr))
return GIT_OBJ_TREE;
else
return GIT_OBJ_BLOB;
}
int git_tree_entry_to_object(
git_object **object_out,
git_repository *repo,
const git_tree_entry *entry)
{
assert(entry && object_out);
return git_object_lookup(object_out, repo, &entry->oid, GIT_OBJ_ANY);
}
static git_tree_entry *entry_fromname(git_tree *tree, const char *name, size_t name_len)
{
int idx = tree_key_search(&tree->entries, name, name_len);
if (idx < 0)
return NULL;
return git_vector_get(&tree->entries, idx);
}
const git_tree_entry *git_tree_entry_byname(git_tree *tree, const char *filename)
{
assert(tree && filename);
return entry_fromname(tree, filename, strlen(filename));
}
const git_tree_entry *git_tree_entry_byindex(git_tree *tree, size_t idx)
{
assert(tree);
return git_vector_get(&tree->entries, idx);
}
const git_tree_entry *git_tree_entry_byoid(git_tree *tree, const git_oid *oid)
{
unsigned int i;
git_tree_entry *e;
assert(tree);
git_vector_foreach(&tree->entries, i, e) {
if (memcmp(&e->oid.id, &oid->id, sizeof(oid->id)) == 0)
return e;
}
return NULL;
}
int git_tree__prefix_position(git_tree *tree, const char *path)
{
git_vector *entries = &tree->entries;
struct tree_key_search ksearch;
unsigned int at_pos;
ksearch.filename = path;
ksearch.filename_len = strlen(path);
/* Find tree entry with appropriate prefix */
git_vector_bsearch3(&at_pos, entries, &homing_search_cmp, &ksearch);
for (; at_pos < entries->length; ++at_pos) {
const git_tree_entry *entry = entries->contents[at_pos];
if (homing_search_cmp(&ksearch, entry) < 0)
break;
}
for (; at_pos > 0; --at_pos) {
const git_tree_entry *entry = entries->contents[at_pos - 1];
if (homing_search_cmp(&ksearch, entry) > 0)
break;
}
return at_pos;
}
unsigned int git_tree_entrycount(const git_tree *tree)
{
assert(tree);
return (unsigned int)tree->entries.length;
}
static int tree_error(const char *str)
{
giterr_set(GITERR_TREE, "%s", str);
return -1;
}
static int tree_parse_buffer(git_tree *tree, const char *buffer, const char *buffer_end)
{
if (git_vector_init(&tree->entries, DEFAULT_TREE_SIZE, entry_sort_cmp) < 0)
return -1;
while (buffer < buffer_end) {
git_tree_entry *entry;
int attr;
if (git__strtol32(&attr, buffer, &buffer, 8) < 0 ||
!buffer || !valid_filemode(attr))
return tree_error("Failed to parse tree. Can't parse filemode");
if (*buffer++ != ' ')
return tree_error("Failed to parse tree. Object is corrupted");
if (memchr(buffer, 0, buffer_end - buffer) == NULL)
return tree_error("Failed to parse tree. Object is corrupted");
/** Allocate the entry and store it in the entries vector */
{
entry = alloc_entry(buffer);
GITERR_CHECK_ALLOC(entry);
if (git_vector_insert(&tree->entries, entry) < 0)
return -1;
entry->attr = attr;
}
while (buffer < buffer_end && *buffer != 0)
buffer++;
buffer++;
git_oid_fromraw(&entry->oid, (const unsigned char *)buffer);
buffer += GIT_OID_RAWSZ;
}
return 0;
}
int git_tree__parse(git_tree *tree, git_odb_object *obj)
{
assert(tree);
return tree_parse_buffer(tree, (char *)obj->raw.data, (char *)obj->raw.data + obj->raw.len);
}
static unsigned int find_next_dir(const char *dirname, git_index *index, unsigned int start)
{
unsigned int i, entries = git_index_entrycount(index);
size_t dirlen;
dirlen = strlen(dirname);
for (i = start; i < entries; ++i) {
git_index_entry *entry = git_index_get_byindex(index, i);
if (strlen(entry->path) < dirlen ||
memcmp(entry->path, dirname, dirlen) ||
(dirlen > 0 && entry->path[dirlen] != '/')) {
break;
}
}
return i;
}
static int append_entry(
git_treebuilder *bld,
const char *filename,
const git_oid *id,
git_filemode_t filemode)
{
git_tree_entry *entry;
entry = alloc_entry(filename);
GITERR_CHECK_ALLOC(entry);
git_oid_cpy(&entry->oid, id);
entry->attr = (uint16_t)filemode;
if (git_vector_insert(&bld->entries, entry) < 0)
return -1;
return 0;
}
static int write_tree(
git_oid *oid,
git_repository *repo,
git_index *index,
const char *dirname,
unsigned int start)
{
git_treebuilder *bld = NULL;
unsigned int i, entries = git_index_entrycount(index);
int error;
size_t dirname_len = strlen(dirname);
const git_tree_cache *cache;
cache = git_tree_cache_get(index->tree, dirname);
if (cache != NULL && cache->entries >= 0){
git_oid_cpy(oid, &cache->oid);
return find_next_dir(dirname, index, start);
}
error = git_treebuilder_create(&bld, NULL);
if (bld == NULL) {
return -1;
}
/*
* This loop is unfortunate, but necessary. The index doesn't have
* any directores, so we need to handle that manually, and we
* need to keep track of the current position.
*/
for (i = start; i < entries; ++i) {
git_index_entry *entry = git_index_get_byindex(index, i);
char *filename, *next_slash;
/*
* If we've left our (sub)tree, exit the loop and return. The
* first check is an early out (and security for the
* third). The second check is a simple prefix comparison. The
* third check catches situations where there is a directory
* win32/sys and a file win32mmap.c. Without it, the following
* code believes there is a file win32/mmap.c
*/
if (strlen(entry->path) < dirname_len ||
memcmp(entry->path, dirname, dirname_len) ||
(dirname_len > 0 && entry->path[dirname_len] != '/')) {
break;
}
filename = entry->path + dirname_len;
if (*filename == '/')
filename++;
next_slash = strchr(filename, '/');
if (next_slash) {
git_oid sub_oid;
int written;
char *subdir, *last_comp;
subdir = git__strndup(entry->path, next_slash - entry->path);
GITERR_CHECK_ALLOC(subdir);
/* Write out the subtree */
written = write_tree(&sub_oid, repo, index, subdir, i);
if (written < 0) {
tree_error("Failed to write subtree");
goto on_error;
} else {
i = written - 1; /* -1 because of the loop increment */
}
/*
* We need to figure out what we want toinsert
* into this tree. If we're traversing
* deps/zlib/, then we only want to write
* 'zlib' into the tree.
*/
last_comp = strrchr(subdir, '/');
if (last_comp) {
last_comp++; /* Get rid of the '/' */
} else {
last_comp = subdir;
}
error = append_entry(bld, last_comp, &sub_oid, S_IFDIR);
git__free(subdir);
if (error < 0) {
tree_error("Failed to insert dir");
goto on_error;
}
} else {
error = append_entry(bld, filename, &entry->oid, entry->mode);
if (error < 0) {
tree_error("Failed to insert file");
goto on_error;
}
}
}
if (git_treebuilder_write(oid, repo, bld) < 0)
goto on_error;
git_treebuilder_free(bld);
return i;
on_error:
git_treebuilder_free(bld);
return -1;
}
int git_tree__write_index(git_oid *oid, git_index *index, git_repository *repo)
{
int ret;
assert(oid && index && repo);
if (index->tree != NULL && index->tree->entries >= 0) {
git_oid_cpy(oid, &index->tree->oid);
return 0;
}
/* The tree cache didn't help us */
ret = write_tree(oid, repo, index, "", 0);
return ret < 0 ? ret : 0;
}
static void sort_entries(git_treebuilder *bld)
{
git_vector_sort(&bld->entries);
}
GIT_INLINE(git_filemode_t) normalize_filemode(git_filemode_t filemode)
{
/* 100664 mode is an early design mistake. Tree entries may bear
* this mode in some old git repositories, but it's now deprecated.
* We silently normalize while inserting new entries in a tree
* being built.
*/
if (filemode == GIT_FILEMODE_BLOB_GROUP_WRITABLE)
return GIT_FILEMODE_BLOB;
return filemode;
}
int git_treebuilder_create(git_treebuilder **builder_p, const git_tree *source)
{
git_treebuilder *bld;
size_t i, source_entries = DEFAULT_TREE_SIZE;
assert(builder_p);
bld = git__calloc(1, sizeof(git_treebuilder));
GITERR_CHECK_ALLOC(bld);
if (source != NULL)
source_entries = source->entries.length;
if (git_vector_init(&bld->entries, source_entries, entry_sort_cmp) < 0)
goto on_error;
if (source != NULL) {
for (i = 0; i < source->entries.length; ++i) {
git_tree_entry *entry_src = source->entries.contents[i];
if (append_entry(
bld, entry_src->filename,
&entry_src->oid,
normalize_filemode((git_filemode_t)entry_src->attr)) < 0)
goto on_error;
}
}
*builder_p = bld;
return 0;
on_error:
git_treebuilder_free(bld);
return -1;
}
int git_treebuilder_insert(
const git_tree_entry **entry_out,
git_treebuilder *bld,
const char *filename,
const git_oid *id,
git_filemode_t filemode)
{
git_tree_entry *entry;
int pos;
assert(bld && id && filename);
if (!valid_filemode(filemode))
return tree_error("Failed to insert entry. Invalid filemode");
filemode = normalize_filemode(filemode);
if (!valid_entry_name(filename))
return tree_error("Failed to insert entry. Invalid name for a tree entry");
pos = tree_key_search(&bld->entries, filename, strlen(filename));
if (pos >= 0) {
entry = git_vector_get(&bld->entries, pos);
if (entry->removed)
entry->removed = 0;
} else {
entry = alloc_entry(filename);
GITERR_CHECK_ALLOC(entry);
}
git_oid_cpy(&entry->oid, id);
entry->attr = filemode;
if (pos < 0) {
if (git_vector_insert(&bld->entries, entry) < 0)
return -1;
}
if (entry_out != NULL) {
*entry_out = entry;
}
return 0;
}
static git_tree_entry *treebuilder_get(git_treebuilder *bld, const char *filename)
{
int idx;
git_tree_entry *entry;
assert(bld && filename);
idx = tree_key_search(&bld->entries, filename, strlen(filename));
if (idx < 0)
return NULL;
entry = git_vector_get(&bld->entries, idx);
if (entry->removed)
return NULL;
return entry;
}
const git_tree_entry *git_treebuilder_get(git_treebuilder *bld, const char *filename)
{
return treebuilder_get(bld, filename);
}
int git_treebuilder_remove(git_treebuilder *bld, const char *filename)
{
git_tree_entry *remove_ptr = treebuilder_get(bld, filename);
if (remove_ptr == NULL || remove_ptr->removed)
return tree_error("Failed to remove entry. File isn't in the tree");
remove_ptr->removed = 1;
return 0;
}
int git_treebuilder_write(git_oid *oid, git_repository *repo, git_treebuilder *bld)
{
unsigned int i;
git_buf tree = GIT_BUF_INIT;
git_odb *odb;
assert(bld);
sort_entries(bld);
/* Grow the buffer beforehand to an estimated size */
git_buf_grow(&tree, bld->entries.length * 72);
for (i = 0; i < bld->entries.length; ++i) {
git_tree_entry *entry = bld->entries.contents[i];
if (entry->removed)
continue;
git_buf_printf(&tree, "%o ", entry->attr);
git_buf_put(&tree, entry->filename, entry->filename_len + 1);
git_buf_put(&tree, (char *)entry->oid.id, GIT_OID_RAWSZ);
}
if (git_buf_oom(&tree))
goto on_error;
if (git_repository_odb__weakptr(&odb, repo) < 0)
goto on_error;
if (git_odb_write(oid, odb, tree.ptr, tree.size, GIT_OBJ_TREE) < 0)
goto on_error;
git_buf_free(&tree);
return 0;
on_error:
git_buf_free(&tree);
return -1;
}
void git_treebuilder_filter(git_treebuilder *bld, int (*filter)(const git_tree_entry *, void *), void *payload)
{
unsigned int i;
assert(bld && filter);
for (i = 0; i < bld->entries.length; ++i) {
git_tree_entry *entry = bld->entries.contents[i];
if (!entry->removed && filter(entry, payload))
entry->removed = 1;
}
}
void git_treebuilder_clear(git_treebuilder *bld)
{
unsigned int i;
assert(bld);
for (i = 0; i < bld->entries.length; ++i) {
git_tree_entry *e = bld->entries.contents[i];
git_tree_entry_free(e);
}
git_vector_clear(&bld->entries);
}
void git_treebuilder_free(git_treebuilder *bld)
{
if (bld == NULL)
return;
git_treebuilder_clear(bld);
git_vector_free(&bld->entries);
git__free(bld);
}
static size_t subpath_len(const char *path)
{
const char *slash_pos = strchr(path, '/');
if (slash_pos == NULL)
return strlen(path);
return slash_pos - path;
}
int git_tree_entry_bypath(
git_tree_entry **entry_out,
git_tree *root,
const char *path)
{
int error = 0;
git_tree *subtree;
const git_tree_entry *entry;
size_t filename_len;
/* Find how long is the current path component (i.e.
* the filename between two slashes */
filename_len = subpath_len(path);
if (filename_len == 0) {
giterr_set(GITERR_TREE, "Invalid tree path given");
return GIT_ENOTFOUND;
}
entry = entry_fromname(root, path, filename_len);
if (entry == NULL) {
giterr_set(GITERR_TREE,
"The path '%s' does not exist in the given tree", path);
return GIT_ENOTFOUND;
}
switch (path[filename_len]) {
case '/':
/* If there are more components in the path...
* then this entry *must* be a tree */
if (!git_tree_entry__is_tree(entry)) {
giterr_set(GITERR_TREE,
"The path '%s' does not exist in the given tree", path);
return GIT_ENOTFOUND;
}
/* If there's only a slash left in the path, we
* return the current entry; otherwise, we keep
* walking down the path */
if (path[filename_len + 1] != '\0')
break;
case '\0':
/* If there are no more components in the path, return
* this entry */
*entry_out = git_tree_entry_dup(entry);
return 0;
}
if (git_tree_lookup(&subtree, root->object.repo, &entry->oid) < 0)
return -1;
error = git_tree_entry_bypath(
entry_out,
subtree,
path + filename_len + 1
);
git_tree_free(subtree);
return error;
}
static int tree_walk(
git_tree *tree,
git_treewalk_cb callback,
git_buf *path,
void *payload,
bool preorder)
{
int error = 0;
unsigned int i;
for (i = 0; i < tree->entries.length; ++i) {
git_tree_entry *entry = tree->entries.contents[i];
if (preorder) {
error = callback(path->ptr, entry, payload);
if (error > 0)
continue;
if (error < 0)
return GIT_EUSER;
}
if (git_tree_entry__is_tree(entry)) {
git_tree *subtree;
size_t path_len = git_buf_len(path);
if ((error = git_tree_lookup(
&subtree, tree->object.repo, &entry->oid)) < 0)
break;
/* append the next entry to the path */
git_buf_puts(path, entry->filename);
git_buf_putc(path, '/');
if (git_buf_oom(path))
return -1;
error = tree_walk(subtree, callback, path, payload, preorder);
if (error != 0)
break;
git_buf_truncate(path, path_len);
git_tree_free(subtree);
}
if (!preorder && callback(path->ptr, entry, payload) < 0) {
error = GIT_EUSER;
break;
}
}
return error;
}
int git_tree_walk(git_tree *tree, git_treewalk_cb callback, int mode, void *payload)
{
int error = 0;
git_buf root_path = GIT_BUF_INIT;
switch (mode) {
case GIT_TREEWALK_POST:
error = tree_walk(tree, callback, &root_path, payload, false);
break;
case GIT_TREEWALK_PRE:
error = tree_walk(tree, callback, &root_path, payload, true);
break;
default:
giterr_set(GITERR_INVALID, "Invalid walking mode for tree walk");
return -1;
}
git_buf_free(&root_path);
return error;
}
